| Summary: | 碩士 === 國立清華大學 === 電機工程學系 === 89 === Three-phase four-wire distribution systems have been widely used in commercial and industrial facilities. And due to the rapid growth of consumer electronics products and power electronics converters in recent years, the resulting harmonics problem has become increasingly serious.
In particular the zero sequence ($3^{rd},9^{th}$,...) harmonics
current drawn by these nonlinear load accumulates in the
neutral conductor and leads to overloading problems on the neutral conductor and the distribution transformer. Such overloading problems raise serious safty concerns. Most of the existing solutions only reduce the overloading in part of the neutral conductor, and require multiple installations to cover the entire neutral conductor.
In this study, a new solution of the neutral harmonic current is proposed for the three-phase four-wire distribution systems. In the proposed scheme,an active filter is connected in series with the neutral conductor. The inverter acts to suppress harmonics in the neutral conductor to prevent overloading.Results have shown that the proposed scheme can
eliminate current harmonics overloading on both the neutral conductor and the distribution transformer with only one active filter installation.
|
|---|
